Author Archive

How Dirty Are You? Part 3…Gloves…The Answers

Read The Question first… Let’s review…we soaked small pieces of different gloves in acetonitrile for 30 minutes. The samples were tested using GC-TOFMS. For relative intensity, a dashed line at the peak height of a 2 ppm PAH standard is drawn on the chromatograms. Which gloves produced the worst background? GREEN GLOVES Bright green, yellow […]

How Dirty Are You? Part 3…Gloves…The Question

This third installment of How Dirty Are You? is all about gloves. Outside of solvent compatibility, there is a lot of room for personal preference regarding the type of lab gloves people can use. I found 5 different gloves in our lab. The bright green gloves and yellow gloves are the two types most often […]

How Dirty Are You? Part 2…Pipet Bulbs…The Answer

Check out the first How Dirty Are You? blog about Parafilm. The How Dirty Are You? pipet bulb blog showed some interesting data…mainly that I need to clean my pipet bulbs and periodically replace them. I am happy to report that I have changed my pipet bulb twice since and even do some solvent rinses. […]

How Dirty Are You? Part 2…Pipet Bulbs…The Question

Check out the first How Dirty Are You? blog about Parafilm®. This How Dirty Are You? blog is all about pipet bulbs. Our lab has 14 people and we have at least a few types of pipet bulbs for both borosilicate glass Pasteur pipets or volumetric pipets. I am sure this isn’t surprising to most […]

Shortcut: AOAC QuEChERS protocol

Here is our checklist style protocol based on the AOAC 2007.01 QuEChERS method. The document describes producing spiked samples at 10 ppb and no spiked samples that are used to determine incurred pesticides. Commodity samples that are not spiked as also used to product matrix-matched standards. During method development we usually test more than one […]

I’ll stop the autosampler and melt the LVI with you…

Another interesting story involving Jack and limited volume inserts (LVI)…. see the first…  

Shortcut: QuEChERS EN and Original Methods Protocol

  I work with a group of colleagues on a lot of projects that use QuEChERS. For more information about QuEChERS take a look at these A Primer, Beyond the Basics, The Concept. We developed a quick protocol for performing generic QuEChERS sample preparation during the method development phase of a project. This type of […]

How Dirty Are You? Part 1 Parafilm®…the Answers!

    Please take a look at the question I posed about Parafilm® and potential contamination. A quick reminder…I was warned against using Parafilm® because it would cause contamination. At the time, I was working with acetonitrile and I didn’t think there was much risk of contamination. We decided to perform a quick test to […]

How Dirty Are You? Part 1 Parafilm®…Take a Quiz!

A couple of years ago I gave a presentation about general lab practices. How dirty are you? Common lab practices that may impact data quality are examined using various gas chromatography and gas chromatography-mass spectrometry techniques. (look for this presentation on the last How Dirty are You? blog…i cant give you the answers now!) We […]

NACRW 2013: Fun (and Science) in the Sun!

  Last week was the 50th Annual Florida Pesticide Residue Workshop…now officially named the North American Chemical Residue Workshop. The conference was held at a beautiful beach resort, but don’t be fooled though there was plenty of science. The program was jammed packed with presentations, panel discussions, forums, posters and exhibits. Topics ranged from pesticide […]